Thomas said early information was that jail staff realized Vincent Barnett, 25, was missing when they did a scheduled inmate count. How he ended up being released still was being looked into, he added.

“We haven't made a complete determination,” Thomas said.

Barnett, who has a lengthy arrest record that includes drug possession and assault-family violence, was sentenced Wednesday on a second-degree felony charge of possession of a controlled substance, according to court records.

The sentencing stems from a Sept. 18, 2011, arrest by the San Antonio Police Department for possession with intent to distribute a controlled substance and a felon in possession of a firearm, records show.